Nitrogen deposition to forest ecosystems with focus on its different forms

Time trends and spatial patterns for wet nitrogen deposition in view of its reduced and oxidized forms for Czech forests are presented. Time trends in NH₄⁺, NO₃^-, and N-NH₄⁺/N-NO₃^- ratio at 15 sites in 1990-2014 were analysed using the Mann-Kendal test. Changes in spatial patterns derived from results of 43 sites in 2005-2014 were also assessed. Our results indicated a slow but convincing change in favour of NH₄⁺. The N-NH₄⁺/N-NO₃^- ratio, both in precipitation and wet deposition, has been increasing steadily, reflecting the changes in reduced and oxidized forms of nitrogen emissions. A similar change has been observed in some other regions and might have negative impacts on ecosystems.

N-NH₄⁺/N-NO₃^- ratio in precipitation and deposition changes in favour of NH₄⁺. This reflects changes in emissions and might have implications for ecosystems.